Inspection system and method

ABSTRACT

An inspection system and a method for measuring physical characteristics of a component using the inspection system is provided, wherein the inspection system includes a light source, a sensing device, a reflecting device, and a retention mount, at least one of which is movably associated with the inspection system. The method includes associating a component with the inspection system, operating the inspection system to cause the light source to emit a collimated light beam propagating along a source optical path, reflecting the collimated light beam via the reflecting device to cause a reflected collimated light beam to be incident upon the component to produce a component silhouette which is incident upon the sensing device, generating image data responsive to the component silhouette and processing the image data to generate resultant data comprising at least one of a plurality of physical characteristics of the component.

RELATED APPLICATIONS

This application is a Continuation-In-Part of co-pending applicationSer. No. 10/460,941 filed Jun. 13, 2003 entitled “Inspection System andMethod,” the contents of which are incorporated herein by reference inits entirety.

FIELD OF THE INVENTION

This disclosure relates generally to a method and system for inspectingcomponents and more particularly to a method and system for opticallyinspecting the physical characteristics of externally threadedcomponents, such as thread gages, screws, bolts and other externallythreaded components having varied configurations.

BACKGROUND OF THE INVENTION

As society becomes increasingly reliant upon technology, mechanical andelectromechanical systems, such as aircraft, automobiles, weaponssystems and power systems, are called upon to perform an ever increasingnumber of functions. One downside to this is that, in some situations, afailure of a single threaded component in the system may cause acatastrophic failure of the entire system possibly resulting in the lossof millions of dollars and hundreds of lives. In an attempt to reducethe probability of a catastrophic systems failure, critical and somenon-critical systems are required to satisfy predetermine operatingtolerances before they may be used. As such, key threaded componentswithin these systems, i.e. threaded components whose failure may cause acatastrophic system failure, such as screws and/or gages, must alsosatisfy operating tolerances. If a threaded component fails to satisfythese required design tolerances and/or performance specifications, adegradation of system performance and/or a total system failure mayoccur resulting in damage to the system and/or injury/loss of life to anoperator.

One of the current systems used for inspecting the physicalcharacteristics of a threaded component employ an attribute inspectionapproach that measures the characteristics of the threaded component viaa contact measurement technique which does not protect product designlimits. This technique uses GO and/or No Go ring gages that areadjusted, or calibrated, to a desired thread measurement via Go and/orNo Go setting plugs. Unfortunately, this technique does not ensure theintegrity of design limits and because this approach is dependent uponhuman interaction, this technique has the disadvantage of being timeconsuming, subjectively inaccurate and unreliably repeatable for tightoperating tolerances, thus permitting threaded components havingdimensionally non-conforming characteristics to pass inspections.Moreover, there is a considerable wear factor on the measuringinstruments, requiring the Go, No Go setting plugs to be inspected andreplaced often.

Another approach used for measuring external thread gages utilizes threewires communicated to the gage being measured. The three wires are of aknown diameter and are typically disposed between the threads of acomponent such that the wires protrude from the threads, wherein twowires are disposed on one side of the threaded component and one wire isdisposed on the opposing side of the threaded component. The diameterover the wires is then measured via a human inspector. Because the wiresare of a known diameter, this allows certain characteristics of thethreads to be determined by measuring the width of the wires disposedbetween the threads. Unfortunately, this approach is also dependent uponhuman interaction. If the inspector measuring the distance over thewires compresses the wires too much, the wires may become deformedresulting in an inaccurate measurement. Additionally, the surface finishof a threaded component may adversely affect the accuracies of thesemeasurements. Moreover, because the wires are loose and are not heldbetween the threads, the wires may be dropped which may result in thewires becoming contaminated with dirt, the wires being lost or, ifsomeone steps on them, the wires being deformed. Furthermore, differentoperators will generate different gage pressures on the wires which maycause erroneous readings. Thus, this approach has the similardisadvantage of being time consuming, subjectively inaccurate andunreliably repeatable for tight operating tolerances, thus alsopermitting threaded components having dimensionally non-conformingcharacteristics to pass inspections. Additionally, the reliability andrepeatability of this measurement is very poor because an operator mustmeasure angles using an optical projection which is also time consuming,inaccurate and often fails to satisfy current product and gagecalibration specifications. As such, the Measurement Uncertainty Factor(MUF) in many situations exceeds the required tolerances and as aresult, the required accuracies for complete certification of thesemethods have thus far been unobtainable.

Therefore, it would be desirable to provide a measurement device that iscapable of accurately, consistently, reliably and quickly measuring thephysical characteristics of a threaded component without humaninteraction.

SUMMARY OF THE INVENTION

An inspection system is provided, wherein the inspection system includesa collimated light source defining a source optical path, the collimatedlight source being operable to cause a collimated light beam topropagate along the source optical path. The inspection system alsoincludes a sensing device defining a sensor optical path, wherein thesensor optical path is substantially perpendicular to the source opticalpath, a positioning device including a positioning device stage and areflecting device, wherein at least one of the collimated light source,the sensing device and the reflecting device is movably disposedrelative to the positioning device and wherein the collimated lightsource and the reflecting device is disposed on the positioning deviceto be within the source optical path to receive the collimated lightbeam, the reflecting device causing a reflected collimated light beam topropagate along the sensor optical path to the sensing device. Theinspection system also includes a retention mount, wherein the retentionmount is disposed within the sensor optical path such that when acomponent is retained within the retention mount, the component blocksat least a portion of the reflected collimated light beam.

A method for measuring physical characteristics of a component using aninspection system including a light source, a sensing device, areflecting device, and a retention mount is provided, wherein at leastone of which is movably associated with the inspection system. Themethod includes associating a component with the inspection system suchthat the component is disposed within the retention mount, operating theinspection system to cause the light source to emit a collimated lightbeam propagating along a source optical path, reflecting the collimatedlight beam via the reflecting device to cause a reflected collimatedlight beam to propagate along a sensor optical path such that thereflected collimated light beam is incident upon the component toproduce a component silhouette which is incident upon the sensingdevice, generating image data responsive to the component silhouette andprocessing the image data to generate resultant data comprising at leastone of a plurality of physical characteristics of the component.

BRIEF DESCRIPTION OF THE DRAWINGS

The above discussed and other features and advantages of the presentinvention will be appreciated and understood by those skilled in the artfrom the following detailed description and drawings wherein likeelements are numbered alike in the several Figures:

FIG. 1 shows a perspective side view of a component inspection system;

FIG. 2 shows a side view of a component inspection system;

FIG. 3 shows a close up side view of a component inspection system;

FIG. 4 shows a front view of a component inspection system;

FIG. 5 shows a close up perspective front view of a component inspectionsystem;

FIG. 6 shows a close up front offset view of a component inspectionsystem having a component disposed between arbors;

FIG. 7 shows a schematic block diagram of a collimated light source;

FIG. 8 shows a front view of a component disposed between arbors of acomponent inspection system;

FIG. 9 shows a schematic block diagram of a component inspection system;

FIG. 10 shows a side view of a threaded component;

FIG. 11 show a side view of a threaded component;

FIG. 12 shows a block diagram illustrating an overall method formeasuring the characteristics of a component using a componentinspection system;

FIG. 13 shows a block diagram illustrating a component/gage selectionalgorithm;

FIG. 14 shows a GUI screen capture of a component/gage selection screen;

FIG. 15 shows a GUI screen capture of a component/gage selection screen;

FIG. 16 shows a GUI screen capture of a component/gage selection screen;

FIG. 17 shows a GUI screen capture of a component/gage selection screen;

FIG. 18 shows a GUI screen capture of a component/gage selection screen;

FIG. 19 shows a block diagram illustrating a calibration algorithm;

FIG. 20 shows a reference arbor knee and a search box;

FIG. 21 shows a display device illustrating lens distortionmeasurements;

FIG. 22 shows a block diagram illustrating a component measurementalgorithm; and

FIG. 23 shows a block diagram illustrating an R&R algorithm.

DETAILED DESCRIPTION OF THE INVENTION

An exemplary embodiment is described herein by way of illustration asmay be applied to the measurement and inspection of threaded gages andproduct, such as screws, bolts and other externally threaded components.However, while an exemplary embodiment is shown and describedhereinbelow, it will be appreciated by those skilled in the art that theinvention is not limited to the embodiment(s) and application(s) asdescribed herein, but also to any component and/or measurement whereaccuracy in tolerance measurement is critical, such as taps, splines,gears, internal bores, integral plane cylindrical bores, internalthreads, internal/external diameters and/or material composition and/orstrength. Moreover, those skilled in the art will appreciate that avariety of potential implementations and configurations are possiblewithin the scope of the disclosed embodiments.

Referring to FIGS. 1-8, an inspection system 100 is shown and described.In accordance with an exemplary embodiment, inspection system 100includes a collimated light source 102, a sensing device 104, areflecting device 106, a component support device 108 and a systemsupport structure 110. System support structure 110 includes a basesupport structure 112, a base structure 114, a bridge structure 116defining a bridge cavity 118, a light source mounting device 120 and asensor mounting device 122. Base support structure 112 is disposed to besupportingly associated with base structure 114 and base structure 114is disposed to be supportingly associated with bridge structure 116,wherein bridge cavity 118 is disposed between bridge structure 116 andbase structure 114.

Collimated light source 102 is preferably associated with base structure114 via light source mounting device 120 such that light emitted fromcollimated light source 102 propagates along a source optical path whichis defined by collimated light source 102 and which is parallel to basestructure 114. Sensing device 104 is preferably associated with bridgestructure 116 via sensor mounting device 122, wherein sensing device 104defines a sensor optical path which perpendicularly intersects thesource optical path. Although, base structure 114 and bridge structure116 are preferably constructed from a non-metallic polymer casting, itis contemplated that base structure 114 and bridge structure 116 may beconstructed from any shock, vibration and/or movement attenuatingmaterial(s) and/or composite(s) suitable to the desired end purpose.

Component support device 108 includes a positioning device 124 and amounting base 126, wherein mounting base 126 is associated with basestructure 114. Positioning device 126 includes a positioning stage 128and a component retainer 130, wherein component retainer 130 isassociated with positioning stage 128 and includes a first arbor 132separated from a second arbor 134 via an arbor cavity 136 and wherein atleast one of first arbor 132 and/or second arbor 134 includes a notchedpotion, or arbor reference “knee” position 220. Positioning stage 128 ispreferably positionally and controllably configurable in all planes(such as x-plane, y-plane, z-plane) relative to mounting base 126 via amotor operated by a motor controller. At least one of first arbor 132and second arbor 134 are configurable for retaining a component withincomponent retainer 130. Reflecting device 106 is preferably associatedwith positioning stage 128 such that reflecting device 106 is disposedat an angle of 45.degree. relative to the surface of positioning stage128 and such that reflecting device 106 is disposed in the same plane asfirst arbor 132, second arbor 134 and arbor cavity 136 (i.e. sensoroptical path). Additionally, component support device 108 is preferablydisposed within bridge cavity 118 such that reflecting device 106 isdisposed at the intersection of the source optical path and the sensoroptical path. Although reflecting device 106 is preferably a highquality mirror having an accuracy of between about 0.10 wave length andabout 0.25 wave length first surface style mirror, reflecting device 106may be any high quality reflective surface device suitable to thedesired end purpose.

Sensing device 104 includes a high resolution camera 137 having amicroscope-type telecentric optical lens 138 and although sensing device104 is preferably powered via an external power source, sensing device104 may be powered using any power source suitable to the desired endpurpose, such as a battery. Moreover, although microscope typetele-centric optical lens 138 preferably has a magnification factor of2.6.times., microscope type tele-centric optical lens 138 may have anymagnification factor suitable to the desired end purpose. Furthermore,although sensing device 104 is a VISICS CCD camera having a microscopetype telecentric optical lens system with 2.6.times. magnification, itis contemplated that sensing device 104 may be any sensing devicesuitable to the desired end purpose.

Referring to FIG. 7, collimated light source 102 includes a LightEmitting Diode (LED) 140, a collimating lens 142 and a lens cap 144having a lens slot 146 disposed to minimize the stray emission of lightemitted from collimating lens 142. In addition, collimated light source102 is preferably associated with base structure 114 such thatcollimating lens 142 is in optical line of sight with reflecting device106. Moreover, although collimated light source 102 is preferablypowered via an external power source, collimated light source 102 may bepowered using any power source suitable to the desired end purpose, suchas a battery.

Inspection system 100 is constructed such that when LED 140 is energizeda beam of light is emitted from LED 140 and is projected such that thebeam of light becomes incident upon collimating lens 142. Collimatinglens 142 collimates the beam of light to create a collimated light beam148, which is then emitted from collimating lens 142. Upon exitingcollimating lens 142, collimated light beam 148 propagates along thesource optical path and becomes incident upon reflecting device 106,which is disposed at an angle of 45.degree. relative to the surface ofpositioning stage 128. Reflecting device 106 then reflects incidentcollimated light beam 148 and the reflected collimated light beam 150propagates along the sensor optical path to become incident upon sensingdevice 104. However, because reflecting device 106 is disposed in thesame plane as first arbor 132, second arbor 134 and arbor cavity 136(i.e. sensor optical path), before reflected collimated light beam 150becomes incident upon sensing device 104, reflected collimated lightbeam 150 becomes incident upon first arbor 132, second arbor 134 andarbor cavity 136. As such, when a component is disposed within componentretainer 130 to be between first arbor 132 and second arbor 134,reflected collimated light beam 150 becomes partially blocked by thecomponent, first arbor 132 and/or second arbor 134 and as a result, ashadow or silhouette of the component, first arbor 132 and/or secondarbor 134 is created and communicated to sensing device 104.

Referring to FIG. 9, an overall block diagram of inspection system 100is shown and described. Inspection system 100 is shown as including aprocessing device 152 having a display device 154, camera controllercircuitry 156 and a communications port 158, wherein processing device152 is disposed to be in communication with collimated light source 102,sensing device 104 and positioning device 124. In accordance with anexemplary embodiment, collimated light source 102 is shown in opticalcommunication with reflecting device 106 such that collimated light beam148 emitted from collimated light source 102 is incident upon reflectingdevice 106. Reflecting device 106 reflects collimated light beam 148 toproduce reflected collimated light beam 150. Sensing device 104 is shownin optical communication with reflecting device 106 such that reflectedcollimated light beam 150 is incident upon sensing device 104 to bereceived by high resolution camera 137 via microscope type tele-centricoptical lens 138. Thus, when a component is disposed between first arbor132 and second arbor 134, the silhouette of the component, first arbor132 and/or second arbor 134 is also received by high resolution camera137.

High resolution camera 137 converts the silhouette image into image dataand communicates this image data to processing device 152, wherein theimage data is responsive to the interaction between the component andreflected collimated light beam 148 received by telecentric optical lens138. Processing device 152 then examines this image data to determine ifmore image data is required. If more image data is required, processingdevice 152 instructs sensing device 104 to obtain more image data. Ifnecessary, processing device 152 may control the position of positioningdevice 126 via communications port 158 to dispose positioning device 126as necessary in a manner responsive to the desired image data. Althoughprocessing device 152 is preferably communicated with positioning device126 via an RS-232 or RS-422 communications port, processing device 152may be communicated with positioning device 126 via any device and/ormethod suitable to the desired end purpose, such as via wirelesscommunications. Moreover, camera controller circuitry 156 may becommunicated with processing device 152 via any method and/or devicesuitable to the desired end purpose. Furthermore, although highresolution camera 137 is preferably an electronic camera being able tosupport an image size of up to at least 1296.times.1016 pixels, highresolution camera 137 may be any high resolution camera 137 suitable tothe desired end purpose.

It is further contemplated that, although display device 150 ispreferably a flat panel display device having a 1280.times.1024 displaycapability, display device 150 may be any display device and/or methodsuitable to the desired end purpose. Additionally, although processingdevice 152 is preferably a computer system operating an MS Windows 2000operating system (or higher version) and having a Pentium processor withat least 128 Mb RAM, Ethernet network capability and a wirelesscommunications device, such as a modem, DSL or Ti line, processingdevice 148 may be any processing device suitable to the desired endpurpose. Positioning device 126 preferably includes a cast iron stagewith a glass slide and a linear motor having crossed rollers withpatented anti-creep technology. The linear motor preferably allows forat least plus and minus three (3) inches of travel in both X and Y axesand allows for a maximum load of at least 635 Kg. Positioning device 126also preferably includes a digital motor (servo) controller having anintegral drive with a digital current loop and is communicated withprocessing device 152 via an RS-232/RS-422 communications port.Additionally, the digital motor (servo) controller is preferably capableof supporting a 10-30 amp peak, 6-15 amps continuous and a 170-300 VDCbus and although the digital motor (servo) controller is preferablycapable of supporting movement in the X and Y axis, it is contemplatedthat digital motor (servo) controller may also be capable of supportingmovement in the Z axis, as well.

Operation of System

Referring to FIG. 10 and FIG. 11, a side view of an externally threadedcomponent, such as a threaded product is shown and discussed. Acomponent thread is a combination of a thread ridge and groove,typically of uniform section, that is produced by forming a groove witha helix on an external or internal surface of a cylinder or cone.Because the component thread is designed to operate in association withan opposing component thread, it is essential that certain key physicalcharacteristics relating to thread size and thread form be tightlycontrolled. As such, it is desirable to measure these thread sizecharacteristics and thread form characteristics as accurately aspossible. The thread size characteristics include the major diameter,the minor diameter, the functional diameter and the pitch diameter andthe thread form characteristics include the pitch, the lead, theuniformity of helix angle, the flank angle and the included angle, eachone of which is discussed in more detail hereinbelow.

The Major Diameter

The major diameter of the component is the diameter or width of animaginary cylinder, called the major cylinder, whose surface would beparallel to the straight axis of the component and whose surface wouldbound the crests of an external thread or the roots of an internalthread. However, although both threaded gages and threaded productstypically have a full form major diameter, threaded gages also typicallyhave a truncated major diameter. As such, a threaded gage includes afull form major diameter and a truncated major diameter and a threadedproduct only includes a full form major diameter. The full form majordiameter, for both a threaded gage and a threaded product, may bedefined as a composite measurement responsive to the major radius (whichmay be defined as the distance between the component axis and onesurface of the major cylinder or one half of the major diameter)measured on the 0.degree. side of the full form threads and the majorradius measured on the 180.degree. side of the full form threads.However, for a threaded gage, the truncated major diameter may bedefined as a composite measurement responsive to the major radiusmeasured on the 0.degree. side of the truncated threads and the majorradius measured on the 180.degree. side of the truncated threads.

The Minor Diameter

The minor diameter of the component is the diameter of an imaginarycylinder, or minor cylinder, whose surface would be parallel to thestraight axis of the component and whose surface would bound the rootsof an external thread or the crests of an internal thread. Thus, theminor radius, which may be defined as the distance between the componentaxis and one surface of the minor cylinder or one half of the minordiameter, and which is typically measured using the first thread on the0.degree. side, is typically determined using a best fit radius that istangential to the flanks and that has no reversals.

The Pitch and Pitch Diameter

The pitch of a thread having uniform spacing may be defined as thedistance, measured parallel to the axis, between corresponding points onadjacent thread forms in the same axial plane and on the side of theaxis. Thus, the pitch may be defined as the number of threads per inch(TPI) and the pitch distance may be defined as 1/TPI, wherein TPI ismeasured parallel to the thread axis, from a point on one flank to thecorresponding point on the next available flank. The pitch diameter ofthe component is the diameter or width of an imaginary cylinder, calledthe pitch cylinder, whose surface would be parallel to the axis of thethread or component and whose surface would intersect the profile of astraight thread such that the width of the thread ridge and the threadgroove are equal.

Thus, the pitch diameter of a threaded gage, which typically includesfull form threads and truncated threads, includes a pitch diameter frontand a pitch diameter back, wherein the pitch diameter front isresponsive to the leading and trailing angles of the thread, the leadand the crest width of the threads at the truncated location and whereinthe pitch diameter back is responsive to the leading and trailing anglesof the thread, the lead and the crest width of the threads at the fullform location. Whereas the pitch diameter of a threaded component, whichtypically includes only full form threads, includes only a pitchdiameter front, wherein the pitch diameter front is responsive to theleading and trailing angles of the thread, the lead and the crest widthof the threads.

The Lead

The lead may be defined as the axial distance moved by the component inrelation to the amount of angular rotation, when a threaded component isrotated about its axis with respect to a fixed mating thread. Thus, thelead is the amount of axial travel when the threaded component is turnedone full turn or 360.degree. and pitch is the distance measured parallelto the axis from a point on one flank to the corresponding point on theadjacent flank. Any deviation in lead tends to increase the functionaldiameter of the external thread (or decrease the functional diameter ofthe internal thread) and rapidly consumes the allowed operating pitchdiameter tolerance of a threaded component. A deviation in lead mayresult in non-engagement of a screw thread with its mating part at allbut a few points. Thus, when the threaded parts are assembled, andtorque is applied, the result is pressure being applied to only a few,and possibly only one pressure flank. As such, any deviation in lead mayproduce a non-engagement condition for some threads and cause a failurein engaging threads at the point of pressure flank engagement due tonon-engagement.

The Uniformity of Helix Angle

The helical path deviation of a thread is a wavy deviation from a truehelical advancement or a non-uniformity of helix angle. In a similarmanner as the lead, a deviation in the helical path causes an increasein the functional size of the component in proportion to the amount ofwaviness. Thus, all of the statements that were made concerning adeviation in lead also apply to a deviation in helical path andsimilarly, a deviation of helical path may result in partial engagementof the thread flanks with the result that torque pressures may not beevenly distributed and may result in pre-load relaxation.

The Flank Angle

The included angle of a thread is the angle between the flanks of thethread measured in an axial plane. The flank angles are the anglesbetween the individual flanks and the perpendicular to the axis of thethread measured in an axial plane. A flank angle of a symmetrical threadis commonly referred to as the half included angle or the half angle ofa thread. A deviation in the flank angle may result in a failure of thethread when the product is exposed to line loads or when torque isapplied. This is because an improper flank engagement may create anunevenly distributed pressure load along the flank rather than thepressure load being distributed evenly along the flank.

Other Physical Characteristics

Other important physical characteristics of the component include thefunctional size diameter, the taper characteristic of the pitch cylinderand the out-of-roundness, all of which can generate a non-engagementcondition. In fact, distortion or deviation from specifications of anyof the physical characteristics discussed herein may cause varyingdegrees of non-engagement.

The Functional Diameter

The functional, or virtual, diameter of a thread (external or internal)may be defined as the resultant size of the product thread taking intoaccount the effect of lead, helical path deviation, flank angledeviation, taper and out-of-roundness, including cylindricity. As such,it may be seen that the functional diameter is the pitch diameter of theenveloping thread of perfect pitch, lead and flank angles, having fulldepth of engagement, but that are clear at crests and roots, ofspecified lengths of engagement. For an external thread, the functionaldiameter may be derived by adding the cumulative effects of deviationsto the pitch diameter (for internal threads subtracting the cumulativeeffects of deviations), including variations in lead and flank anglesover a specified length of engagement. Thus, it should be clear that theeffects of taper, out-of-roundness and surface defects may be positiveor negative on either external or internal threads, respectively.

The Taper Characteristic of the Pitch Cylinder

The taper characteristic of the pitch cylinder is simply a tapering ofthe pitch cylinder of the thread. As can be seen, a tapered thread failsto give a complete thread engagement, which may lead to a productfailure caused by uneven torque pressure conditions on pressure flanksand pre-load relaxation.

The Out-of-Roundness of the Pitch Cylinder

The out-of-roundness of the pitch cylinder, which is any deviation ofthe pitch cylinder from round, limits the thread engagement and allowsfor point or line contact with the mating thread and typically includestwo types of out-of-roundness: Multi-lobe or Oval.

Overall Method of Operation

With the desired physical characteristics of a threaded component to bemeasured explained hereinabove, an overall method for measuring thesecharacteristics is provided and described hereinbelow. Furthermore, itis contemplated that each of the methods, calculations and algorithmsdescribed herein, may be performed via a system operator and/or via anautomated system.

Referring to FIG. 12, an overall method 300 for measuring thecharacteristics of a component using inspection system 100 is shown anddiscussed. In accordance with an exemplary embodiment, inspection system100 and component 162 is preferably obtained, as shown in block 302,wherein inspection system 100 includes a light source 102, a sensingdevice 104, a reflecting device 106, and a component support device 108.Information regarding the type of threaded component 162 such as ascrew, gage, bolt and/or other component, to be measured is determinedand communicated to inspection system 100 via system software, as shownin block 304. Although, this is preferably accomplished via a systemoperator who enters information regarding threaded component 162 intoprocessing device 152 via a mouse or keyboard in a manner responsive toa component/gage selection algorithm 400. It is contemplated thatcomponent information may be stored in a database and retrieved viasensors, such as bar code readers.

Once component 162 has been selected and component informationcommunicated to processing device 152 has been completed, component 162is associated with inspection system 100 to be disposed within componentsupport device 108, as shown in block 306. This may be accomplished by asystem operator disposing component 162 within component retainer 130such that component 162 is retained within arbor cavity 136 via firstarbor 132 and second arbor 134. Inspection system 100 is then operatedto perform a pre-calibration lens distortion analysis to determine anyparabolic lens distortion factors, as shown in block 308. Thispre-calibration lens distortion analysis is a curve fitting routine thatis performed prior to the calibration procedure and that is separatefrom the system lens distortion measurement and correction that is partof the calibration procedure and that is used to compensate for anyparabolic distortion that is inherent in optical lens 138. Although, itwill be appreciated that the lens distortion analysis is advantageouslyprovided by the lens manufacturer, it is contemplated that any suitablelens distortion analysis method may be independently developed and/orused.

In order to perform this analysis, collimated light source 102 emits acollimated light beam that becomes incident upon reflecting device 106,thus causing a reflected collimated light beam to become incident uponsensing device 104. Sensing device 104 receives this reflectedcollimated light beam and generates image data responsive to thisreflected collimated light beam. Because the reflected collimated lightbeam is unimpeded, the image data generated by sensing device 104 isonly responsive to the characteristics of collimated light source 102,reflecting device 106 and sensing device 104. Thus, the image data mayadvantageously be examined to determine if lens 138 of sensing device104 contains any imperfections or distortions. As such, processingdevice 152 examines the image data to determine whether any variationsof image intensity exist within a predefined field of view of lens 138.This is preferably accomplished by examining portions of the generatedimage data responsive to a number of various image locations within thefield of view of lens 138, wherein the examined portions are responsiveto locations within the vertical and horizontal span of the field ofview, ranging from the bottom to the top and from the left hand side tothe right hand side of the field of view.

For example, the image data to be examined preferably includes datapoints responsive to a plurality of locations on lens 138 that representthe vertical span of lens 138 (or of the field of view of lens 138) forboth the 0.degree. and 180.degree. side of at least one arbor. Theresults for each of these data points, which represent the actualvertical distortion characteristics of lens 138, are then plotted on anactual vertical gradient chart (and compared with an ideal verticalgradient chart provided by the manufacturer of lens 138, wherein theideal vertical gradient chart represents the ideal lens characteristics.In a similar fashion, the image data to be examined also preferablyincludes data points responsive to a plurality of locations on lens 138that represent the horizontal span of lens 138 (or of the field of viewof lens 138). As above, the results for each of these data points, whichrepresent the actual horizontal distortion characteristics of lens 138,are then plotted on an actual horizontal gradient chart and comparedwith an ideal horizontal gradient chart provided by the manufacturer oflens 138, wherein the ideal horizontal gradient chart represents ideallens characteristics. Any deviations between the actualvertical/horizontal gradient charts and the ideal vertical/horizontalgradient charts are recorded and stored for later application insubsequent calculations and/or measurements. It should be noted that, inorder to minimize any effect of lens distortion on the measurements, theareas of interest, i.e. areas of component 162 to be measured, arealmost always disposed in the center of the field of view for lens 138.

Once this has been completed, inspection system 100 is operated to causepositioning stage 128 to be disposed such that the reflected collimatedlight beam is incident upon component 162, as shown in block 310. Thereflected collimated light beam incident upon component 162 produces asilhouette of component 162 and/or first arbor 132 which is projected tobe incident upon sensing device 104. Sensing device 104 generates imagedata responsive to silhouette of component 162 and first arbor 132 andcommunicates this image data to processing device 152 which processesthe image data to generate resultant data, as shown in block 312.Processing device 152 then instructs inspection system 100 to perform asystem calibration in a manner responsive to a predetermined calibrationalgorithm 500, as shown in block 314. Upon completion of predeterminedcalibration algorithm 500, inspection system 100 performs a componentmeasurement in a manner responsive to a predetermined componentmeasurement algorithm 600, predetermined calibration algorithm 500and/or the results of lens distortion analysis, as shown in block 316.Once the component measurement has been completed, component informationis then displayed to the system operator via display device 154 and/orvia a printed certificate or report. In accordance with an exemplaryembodiment, component/gage selection algorithm 400, predeterminedcalibration algorithm 500 and predetermined component measurementalgorithm 600 are discussed in more detail below.

Component/Gage Selection Algorithm

Referring to FIG. 13, a block diagram of a component/gage selectionalgorithm 400 is shown and described. It should be noted that althoughcomponent/gage selection algorithm 400 is described for component/gageselection screen 214 herein, as configured for a threaded product,component/gage selection algorithm 400 may be modified as required forvarious component selections.

Referring to FIG. 14, upon starting inspection system 100, acomponent/gage selection screen 200 is displayed to a system operatorvia display device 154. Component/gage selection screen 200 ispreferably created in a Graphical User Interface (GUI) format having aplurality of pull-down menus 202 and software buttons 204 thatadvantageously allow known physical characteristics of a component to bemeasured to be communicated to inspection system 100 via a mouse and/orkeyboard. Pull-down menus 202 preferably include at least one of acomponent size selection pull down menu 206, a TPI pull down menu 208, aClass selection pull down menu 210 and a thread length pull down menu211 and software buttons 204 preferably include at least one of a unitselection button 212, a component selection button 214, a set plug/workplug selection button 216 and a go/not go selection button 218. It iscontemplated that component selection button 214 advantageously allowsfor the selection of a plurality of types of components to be inspected,including a plain diameter gage, a threaded gage, a product, anX-calibration block, a Y-calibration block and a Roll. It is furthercontemplated that pull-down menus 202 and software buttons 204 aredisplayed to a system operator in a manner responsive to componentselection button 214.

For example, referring to FIG. 15, if component selection button 214 isconfigured for a plain diameter gage, plurality of pull-down menus 202and plurality of selection buttons 204 displayed to a system operatorinclude at least one of a unit selection button 212 and a plain diametergage size pull down-menu 213. Referring to FIG. 16, if componentselection button 214 is configured for a threaded gage, plurality ofpull-down menus 202 and plurality of selection buttons 204 displayed toa system operator include at least one of unit selection button 212, setplug/work plug selection button 216, go/not go selection button 218,component size selection pull down menu 206, TPI pull down menu 208 andClass selection pull down menu 210. Referring to FIG. 17, if componentselection button 214 is configured for a threaded product, plurality ofpull-down menus 202 and plurality of selection buttons 204 displayed toa system operator include at least one of a unit selection button 212,set plug/work plug selection button 216, go/not go selection button 218,component size selection pull down menu 206, TPI pull down menu 208,Class selection pull down menu 210 and a thread length menu 211.Additionally, when component selection button 214 is configured for athreaded product, a pitch diameter measurement menu 217 may bedisplayed. Referring to FIG. 18, a component/gage selection screen 202is shown for component selection button 214 configured for a calibrationblock.

In the case of a threaded component 162, once component/gage selectionscreen 200 is displayed, the system operator selects the system of unitsinspection system 100 is to use when measuring threaded component 162,such as English or Metric units, via unit selection button 212, as shownin block 402. The system operator then selects the type of componentthat inspection system 100 will be measuring (i.e. a threadedcomponent), via gage/product selection button 214, as shown in block404, and (in the case of a gage) whether it is a set plug or a workplug, via set plug/work plug selection button 216, as shown in block406. Also in the case of a gage, once this has been accomplished, thesystem operator selects whether this is a go or not/go, via go/not goselection button 218, and the gage size of the component is selected,via gage size selection pull-down menu 206, as shown in block 408. Inthe case of a component, the Threads Per Inch (TPI) and the Class of thecomponent are then selected, via TPI pull down menu 208, as shown inblock 410 and Class selection pull down menu 210, respectively, as shownin block 412.

Predetermined Calibration Algorithm

Upon completion of the system startup procedure, inspection system 100begins performing a system calibration procedure responsive topredetermined calibration algorithm 500. Referring to FIG. 19 and FIG.20, once the system calibration procedure has been initiated,positioning stage 128 is moved to a predetermined starting position, orHOME position, as shown in block 502. It is contemplated that anylocation of positioning stage 128 may be selected as the HOME position.At this point, all encoders are zeroed and all positional measurementsare determined with reference to this HOME position. An Arbor referenceadjustment is then performed to properly locate the arbor reference“knee” position 220, as shown in block 404, wherein arbor reference“knee” position 220 is a notch disposed on at least one of first arbor132 and/or second arbor 134. A software “constraint window” or searchbox is created within the field of view of lens 138 and image datarepresenting the image contained within this search box is then examinedto locate arbor reference “knee” position 220. Arbor reference “knee”position 220 may preferably be located by analyzing this image data fordifferences in pixel intensities to identify where the horizontal arborsurface ends and the vertical arbor surface begins. This vertical arborsurface is arbor reference “knee” position 220. Once arbor reference“knee” position 220 is located, blue crosshairs 222 are disposed atarbor reference “knee” position 220 and displayed to the system operatorvia display device 154 to advantageously allow the system operator tovisually confirm arbor reference “knee” position 220. It should bestated that arbor reference “knee” position 220 must be contained withthis search box for predetermined calibration algorithm to continue. Ifarbor reference “knee” position 220 is not disposed within the searchbox, predetermined calibration algorithm terminates.

In accordance with an exemplary embodiment, the lens system distortionmeasurements are then conducted, as shown in block 506. Referring toFIG. 21, this is preferably accomplished by operating inspection system100 such that positioning stage 128 relocates arbor reference “knee”position 220 to four distinct position/locations within the field ofview of lens 138 on the 0.degree. side of at least one of first arbor132 and/or second arbor 134. These four distinct position/locations arelocated at a lower vertical field of view position 135, a lower middlevertical field of view position 137, a upper middle vertical field ofview position 139 and an upper vertical field of view position 141. Ateach of these four vertical locations, three horizontal measurements aremade and include a left measurement 143, a center measurement 145 and aright measurement 147. This measurement data is preferably obtained byobserving and/or analyzing the image data corresponding to theparticular points of measurement. The results of thisobservation/analysis are then recorded for use in subsequentcalculation. This sequence is then repeated on the 180.degree. side ofat least one of first arbor 132 and/or second arbor 134. It iscontemplated that a total of 24 measurements (i.e. 12 on the 0.degree.side and 12 on the 180.degree. side) are stored and thus, become part ofthe calculated lens distortion measurement performed near the end of thecalibration cycle. As discussed above, the lens system distortionroutine, and thus the distortion equations, is preferably provided bythe manufacturer of lens system 138.

Once the lens system distortion measurements have been conducted, theX-Axis calibration is performed, as shown in block 508. The X-Axiscalibration may preferably be accomplished by locating the centerposition, the left extreme and the right extreme of field of view 230 oflens 138 and using these data points to calculate the inches per step,inches per pixel and/or the steps per inch calibration factors for theX-Axis. One way to determine center position, left extreme and rightextreme of field of view 230 is to move arbor reference knee position220 to the extreme left hand side of field of view 230 and register thislocation as the left extreme. Arbor reference knee position 220 is thenmoved to the extreme right hand side of field of view 230 and thislocation is registered as the right extreme. Arbor reference kneeposition 220 should then be moved to a point midway between the leftextreme and the right extreme of field of view 230. This point will bethe center of field of view 230 and should be registered as the centerposition. This advantageously ensures minimal distortion from lens 138.

Upon completion of the X-Axis calibration, a Y-Axis calibration at the1.sup.st 0.degree. diameter is performed, as shown in block 510. TheY-Axis calibration at the 1.sup.st 0.degree. diameter is preferablyaccomplished by using the lower middle center location and upper middlecenter location obtained during the lens system distortion measurementto calculate the inches per step, inches per pixel and/or the steps perinch calibration factors for the Y-Axis. The lower middle verticallocation is then determined and is used to measure the radius for the0.degree. side (which may later be added to the radius for the180.degree. side to determined the diameter of the arbor).

Upon completion of the Y-Axis calibration at the 1.sup.st 0.degree.diameter, a Y-Axis 2.sup.nd 0.degree. diameter determination isperformed, as shown in block 512. The determination of the Y-Axis2.sup.nd 0.degree. diameter is preferably accomplished by movingpositioning stage 128 such that arbor reference knee position 220 on the0.degree. side of the arbor is disposed at a lower vertical location, alower middle vertical location, an upper middle vertical location and anupper vertical location of field of view 230. At each of theselocations, inspection system 100 performs three horizontal measurements,a left horizontal measurement, a center horizontal measurement and aright horizontal measurement. This data is preferably stored and maybecome part of the calculated lens distortion factors determined towardthe end of the calibration cycle. It should be noted that the lowermiddle vertical location may be the final position to be measured andmay be used to measure the radius for the 180.degree. side, which maylater be added to the radius of the 0.degree. side to determine thearbor diameter.

Upon completion of the Y-Axis 2.sup.nd 0.degree. diameter determination,a Y-Axis 2.sup.nd diameter determination is performed, as shown in block514. The determination of the Y-Axis 2.sup.nd diameter is preferablyaccomplished by moving the left arbor reference location to determinethe location of the arbor relative to the right arbor reference and lens138. A single measurement is taken in the center of field of view 230 tominimize distortion and is used to determine the radius and to computethe tangent correction factor that is used to compensate for anymisalignment of the Y-Axis of positioning stage 128 with the Y-Axis oflens 138.

Once this has been completed, a Y-Axis 2.sup.nd 180.degree. diameterdetermination is performed, as shown in block 516, by moving positioningstage 128 to the 180.degree. side (same X-Axis position) to measure theradius. The Y-Axis tangent correction factor is then determined, asshown in block 518. This advantageously compensates for a component thatmay be disposed between first arbor 132 and second arbor 134 in anon-level (i.e. horizontal) manner. Moreover, this may preferably beaccomplished by using the measurements taken at the right and left sidesof the arbor and both the X and Y measurement information from theencoders and the image measurement tools are used to compute the tangentcorrection factor. It should be noted that all subsequent Y-Axismeasurements include this compensation factor. All of the informationobtained above are then used to determine the lens distortion factor, asshown in block 520, which is then used for all subsequent X and Ymeasurements, including any light source and/or system stage positionaldistortions/errors (i.e. Abbe* stage errors).

Predetermined Component Measurement Algorithm

It is contemplated that predetermined component measurement algorithm600 is responsive to the component being measured. As such,predetermined component measurement algorithm 600 is explained forvarious types of components to be measured and includes a threadedproduct and a threaded gage. It will be appreciated that allmeasurements are preferably conducted by observing and/or analyzingimage data to determine desired points of interest on threaded component162, such as the thread ridges and grooves. These points of interest arepreferably located by examining the image data and identifyingvariations in pixel intensities to establish silhouette edge points ofthreaded component 162. Once these points of interest have beenidentified, desired physical characteristics of threaded component 162may be determined using known mathematical, geometric and/ortrigonometric relationships.

Upon completion of predetermined calibration algorithm 500, positioningstage 128 is positioned back to arbor reference knee position 220 andcomponent measurement algorithm 600 is initiated, as shown FIG. 22. Atthis point, the Flank registration is performed, as shown in block 602.This is preferably accomplished by disposing positioning stage 128 suchthat component 162 is positioned to an initial X and Y location bymoving positioning stage 128 one half inch away from arbor referenceknee position 220 in the X direction and toward component 162.Positioning stage 128 is then moved in the Y direction such that thelower limit of the pitch diameter at the centerline of field of view 230is approximated. A software measurement tool is then placed at thecenterline to find the flank angel crossings at the centerline. Thestage is then moved again away from arbor reference knee position 220 inthe X-axis direction to align the minor diameter with the left edge offield of view 230. All subsequent measurements rely on moving in pitchlead increments in the X-axis direction. It should be noted that thepitch lead increments are determined by the component selection and arepublished at the top of the Lead Standards readouts. It will beappreciated that, for threaded gages, the truncated measurements will beconducted at thread #2 and the full form measurements will be conductedat thread #6. The term 4X refers to the number of threads for the thirdlead measurement and indicates that it is being made over a span of fourthreads and the term /10 indicates that there are ten threads availableon this component.

Once the flank registration has been performed, the 1.sup.st full thread0.degree. side truncated measurements are conducted, as shown in block604. This may preferably be accomplished by repositioning positioningstage 128 on the first thread on the 0.degree. side designated as thetruncated thread location. This designation is dependent upon the threadnumbers and thus upon the selection of component 162. Using thesilhouette image data, processing device 152 then determines the minorradius, the major radius (for set plug only), the pitch radius, the leadpitch, the lead/trail flank angles and the included angles. The majorradius is determined via the major diameter, which is a compositemeasurement based on the major radius of the 0.degree. and corresponding180.degree. side of the threads. Thus, the major radius is determined bysumming the individual measurements along the thread flat and dividingby the number of measurements collected. The number of measurementlocations may be determined by taking 70% of the thread width, asdetermined by predetermined thread tables, and centering them on thecenter of the thread. This major radius average is then combined fromboth the 0.degree. and the 180.degree. sides to get the major diameter.For a gage, this process is performed for both truncated and full formlocations and for a product, this process is performed only for the fullform location.

The pitch diameter calculation (for both truncated and full formlocation), which is based on the leading and trailing angles, majordiameter, pitch lead and crest width at the location in question (i.e.truncated or full form), may be determined by the equation:PD=MD−(Cot(PL/2)−CW),where, PD is pitch diameter, MD is major diameter, PL is pitch lead andCW is crest width. The lead front measurement, which is responsive tothe difference between the groove distance and the ridge distance alongthe leading/trailing/leading flanks may be determined by positioning asoftware measurement tool along the X-axis and moving the toolvertically around the pitch diameter until the groove distance minus theridge distance is minimized. The tool is then repositioned at theminimized location and the groove distance and the ridge distance areadded to determine the lead front. The lead back measurement, which isresponsive to the difference between the groove distance and the ridgedistance along the trailing/leading/trailing flanks may similarly bedetermined by positioning a software measurement tool along the X-axisand moving the tool vertically around the pitch diameter until thegroove distance minus the ridge distance is minimized. The tool is thenrepositioned at the minimized location and the groove distance and theridge distance are added to determine the lead back.

The multi thread lead, which is responsive to the distance between thelead front and the lead back measurements, may now be determined.Additionally, the lead angle may be determined by an optimistictheoretical line of best fit along the leading flanks of the thread onthe 0.degree. side at the truncated location. The trailing angle may bedetermined by an optimistic theoretical line of best fit along thetrailing flanks of the thread on the 0.degree. side at the truncatedlocation. The included angle may then be determined by adding theleading angle and trailing angle.

At this point, the 2.sup.nd thread 0.degree. side full form measurementsare then made, as shown in block 606. This preferably may beaccomplished by repositioning positioning stage 128 on the second threadon the 0.degree. side designated as the full form thread location. Asdiscussed above, this designation is dependent upon the thread numbersand thus upon the selection of component 162. Using the silhouette imagedata, processing device 152 then determines the minor radius, the majorradius, the pitch radius and the lead pitch.

The 1.sup.st full thread 180.degree. side truncated measurements arethen conducted, as shown in block 608, and are preferably accomplishedby repositioning positioning stage 128 on the first thread on the180.degree. side designated as the truncated thread location. Using thesilhouette image data, processing device 152 then determines the minorradius, the major radius (for set plug only), the pitch radius and thelead pitch.

The 2.sup.nd thread 180.degree. side full form measurements are thenmade, as shown in block 610. This is preferably accomplished byrepositioning positioning stage 128 on the second thread on the180.degree. side designated as the full form thread location. Using thesilhouette image data, processing device 152 then determines the majorradius, the pitch radius and the lead pitch.

The component values and limits are then updated and the results aredisplayed to a system operator and/or printed out in certificate formand positioning stage 128 is repositioned to arbor reference kneeposition 220, as shown in block 612.

It is further contemplated that inspection system 100 may perform an R&R(reliability & repeatability) measurement procedure in a mannerresponsive to a predetermined R&R algorithm 700. Referring to FIG. 23, ablock diagram illustrating predetermined R&R algorithm 700 is shown anddiscussed. Upon initiation of predetermined R&R algorithm 700,positioning stage 128 is positioned into the load position and component162 is disposed to be retained between first arbor 132 and second arbor134, as shown in block 702. R&R algorithm 700 is then activated, asshown in block 704. As discussed hereinabove, inspection system 100 thenperforms predetermined calibration algorithm 500 and predeterminedcomponent measurement algorithm 600, as shown in block 706. At thispoint, once predetermined component measurement algorithm 600 has beencompleted, the system operator may elect to have inspection system 100pause every seven cycles for rotation of component 162, as shown inblock 708. The measurement cycle may then repeated as many times asdesired and the results may then be displayed to the system operator viadisplay device 154 or via a printed certificate or report, as shown inblock 710.

In accordance with an additional embodiment, it should be appreciatedthat the inspection system 100 may also operate by configuring otherelements of the inspection system 100 other than the positioning stage128, such as by moving at least one of the collimated light source 102,the sensing device 104 and/or the reflecting device 106. For example,instead of the positioning stage 128 being positionally and controllablyconfigurable in all planes (such as x-plane, y-plane, z-plane) relativeto the mounting base 126 via a motor operated by a motor controller, atleast one of the collimated light source 102, the sensing device 104and/or the reflecting device 106 may be positionally and controllablyconfigurable in all planes (such as x-plane, y-plane, z-plane) relativeto the mounting base 126 via at least one motor operated by at least onemotor controller such that the component being measured is keptstationary.

In this embodiment, the at least one collimated light source 102, thesensing device 104 and/or the reflecting device 106 may be positionallyand controllably configurable in all planes (such as x-plane, y-plane,z-plane) relative to the mounting base 126 via communications port 158as necessary in a manner responsive to the desired image data. The atleast one collimated light source 102, the sensing device 104 and/or thereflecting device 106 may be positionally and controllably configurablein all planes (such as x-plane, y-plane, z-plane) relative to themounting base 126 using the processing device 152 which may becommunicated with the at least one motor controller via an RS-232 and/oran RS-422 communications port and/or any device and/or method suitableto the desired end purpose, such as via wireless communications.

In this embodiment the inspection system 100 may be operated asdiscussed hereinbefore. For example, consider the overall method 300 formeasuring the characteristics of the component 162. Once thepre-calibration lens distortion analysis has been conducted, theinspection system 100 may be operated to cause the at least onecollimated light source 102, the sensing device 104 and/or thereflecting device 106 to be disposed such that the reflected collimatedlight beam is incident upon component 162, as shown in operational block310. The reflected collimated light beam incident upon component 162produces a silhouette of component 162 and/or first arbor 132 which isprojected to be incident upon the sensing device 104. As discussedhereinbefore, the sensing device 104 generates image data responsive tothe silhouette of the component 162 and the first arbor 132 andcommunicates this image data to processing device 152 which processesthe image data to generate resultant data, as shown in operational block312. The processing device 152 then instructs the inspection system 100to perform a system calibration in a manner responsive to thepredetermined calibration algorithm 500, as discussed in further detailherein and as shown in operational block 314. Upon completion of thepredetermined calibration algorithm 500, the inspection system 100performs a measurement of the component 162 in a manner responsive tothe predetermined component measurement algorithm 600 as discussed infurther detail herein, the predetermined calibration algorithm 500and/or the results of lens distortion analysis, as shown in operationalblock 316. Once the component measurement has been completed, componentinformation may then be displayed to the system operator via the displaydevice 154 and/or via the printed certificate or report.

As above, upon completion of the system startup procedure, theinspection system 100 may begin by performing a system calibrationprocedure responsive to the predetermined calibration algorithm 500.Referring again to FIG. 19 and FIG. 20, once the system calibrationprocedure has been initiated, the at least one collimated light source102, the sensing device 104 and/or the reflecting device 106 may beconfigured to be disposed in a HOME position, as shown in operationalblock 502., wherein it is contemplated that any location of at least onecollimated light source 102, the sensing device 104 and/or thereflecting device 106 may be selected as the HOME position. At thispoint, all encoders are zeroed and all positional measurements aredetermined with reference to this HOME position. An Arbor referenceadjustment is then performed to properly locate the arbor reference“knee” position 220, as shown in operational block 504, wherein thearbor reference “knee” position 220 is a notch disposed on at least oneof first arbor 132 and/or second arbor 134. A software “constraintwindow” or search box is created within the field of view of lens 138and image data representing the image contained within this search boxis then examined to locate arbor reference “knee” position 220. Arborreference “knee” position 220 may be located by analyzing this imagedata for differences in pixel intensities to identify where thehorizontal arbor surface ends and the vertical arbor surface begins.This vertical arbor surface is arbor reference “knee” position 220. Oncearbor reference “knee” position 220 is located, blue crosshairs 222 aredisposed at arbor reference “knee” position 220 and displayed to thesystem operator via display device 154 to allow the system operator tovisually confirm arbor reference “knee” position 220. It should bestated that arbor reference “knee” position 220 must be contained withthis search box for predetermined calibration algorithm to continue. Ifarbor reference “knee” position 220 is not disposed within the searchbox, predetermined calibration algorithm terminates.

As discussed in more detail hereinbefore, the lens system distortionmeasurements may then be conducted, as shown in operational block 506.Referring again to FIG. 21, this may be accomplished by operatinginspection system 100 such that the at least one collimated light source102, the sensing device 104 and/or the reflecting device 106 isconfigured to locate the arbor reference “knee” position 220 to fourdistinct position/locations within the field of view of lens 138 on the0° side of at least one of first arbor 132 and/or second arbor 134.These four distinct position/locations are located at a lower verticalfield of view position 135, a lower middle vertical field of viewposition 137, a upper middle vertical field of view position 139 and anupper vertical field of view position 141. At each of these fourvertical locations, three horizontal measurements are made and include aleft measurement 143, a center measurement 145 and a right measurement147. This measurement data may be obtained by observing and/or analyzingthe image data corresponding to the particular points of measurement.The results of this observation/analysis may then be recorded for use insubsequent calculation. This sequence is then repeated on the 180° sideof at least one of first arbor 132 and/or second arbor 134. It should beappreciated that a total of 24 measurements (i.e. 12 on the 0° side and12 on the 180° side) are stored and thus, become part of the calculatedlens distortion measurement performed near the end of the calibrationcycle. As discussed above, the lens system distortion routine, and thusthe distortion equations, may be provided by the manufacturer of lenssystem 138 or may be generated responsive to the component to beinspected.

Once the lens system distortion measurements have been conducted, theX-Axis calibration is performed, as shown in operational block 508. TheX-Axis calibration may be accomplished by locating the center position,the left extreme and the right extreme of field of view 230 of lens 138and using these data points to calculate the inches per step, inches perpixel and/or the steps per inch calibration factors for the X-Axis. Oneway to determine center position, left extreme and right extreme offield of view 230 is to move arbor reference knee position 220 to theextreme left hand side of field of view 230 and register this locationas the left extreme. Arbor reference knee position 220 is then moved tothe extreme right hand side of field of view 230 and this location isregistered as the right extreme. Arbor reference knee position 220should then be moved to a point midway between the left extreme and theright extreme of field of view 230. This point will be the center offield of view 230 and should be registered as the center position. Thisensures minimal distortion from lens 138.

Upon completion of the X-Axis calibration, a Y-Axis calibration at the1^(st) 0° diameter is performed, as shown in operational block 510. TheY-Axis calibration at the 1^(st) 0° diameter may be accomplished byusing the lower middle center location and upper middle center locationobtained during the lens system distortion measurement to calculate theinches per step, inches per pixel and/or the steps per inch calibrationfactors for the Y-Axis. The lower middle vertical location is thendetermined and is used to measure the radius for the 0° side (which maylater be added to the radius for the 180° side to determined thediameter of the arbor).

Upon completion of the Y-Axis calibration at the 1^(st) 0° diameter, aY-Axis 2^(nd) 0° diameter determination is performed, as shown inoperational block 512. The determination of the Y-Axis 2^(nd) 0°diameter may be accomplished by configuring the at least one collimatedlight source 102, the sensing device 104 and/or the reflecting device106 such that arbor reference knee position 220 on the 0° side of thearbor is disposed at a lower vertical location, a lower middle verticallocation, an upper middle vertical location and an upper verticallocation of field of view 230. At each of these locations, inspectionsystem 100 performs three horizontal measurements, a left horizontalmeasurement, a center horizontal measurement and a right horizontalmeasurement. This data may be stored and may become part of thecalculated lens distortion factors determined toward the end of thecalibration cycle. It should be appreciated that the lower middlevertical location may be the final position to be measured and may beused to measure the radius for the 180° side, which may later be addedto the radius of the 0° side to determine the arbor diameter.

Upon completion of the Y-Axis 2^(nd) 0° diameter determination, a Y-Axis2^(nd) diameter determination is performed, as shown in operation block514. The determination of the Y-Axis 2^(nd) diameter may be accomplishedby moving the left arbor reference location to determine the location ofthe arbor relative to the right arbor reference and lens 138. A singlemeasurement is taken in the center of field of view 230 to minimizedistortion and is used to determine the radius and to compute thetangent correction factor that is used to compensate for anymisalignment of the Y-Axis of positioning stage 128 with the Y-Axis oflens 138.

Once this has been completed, a Y-Axis 2^(nd) 180° diameterdetermination is performed, as shown in operational block 516, byconfiguring the at least one collimated light source 102, the sensingdevice 104 and/or the reflecting device 106 to the 180° side (sameX-Axis position) to measure the radius. The Y-Axis tangent correctionfactor is then determined, as shown in operation block 518. Thiscompensates for a component that may be disposed between first arbor 132and second arbor 134 in a non-level (i.e. horizontal) manner. Moreover,this may be accomplished by using the measurements taken at the rightand left sides of the arbor and both the X and Y measurement informationfrom the encoders and the image measurement tools are used to computethe tangent correction factor. It should be noted that all subsequentY-Axis measurements include this compensation factor. All of theinformation obtained above may then be used to determine the lensdistortion factor, as shown in operational block 520, which is then usedfor all subsequent X and Y measurements, including any light sourceand/or system stage positional distortions/errors (i.e. Abbe* stageerrors).

Referring again to the predetermined component measurement algorithm 600and upon completion of the predetermined calibration algorithm 500, theat least one collimated light source 102, the sensing device 104 and/orthe reflecting device 106 may be positioned back to arbor reference kneeposition 220 and component measurement algorithm 600 is initiated, asshown FIG. 22. At this point, the Flank registration is performed, asshown in operational block 602. This may be accomplished by disposingthe at least one collimated light source 102, the sensing device 104and/or the reflecting device 106 such that component 162 is positionedto an initial X and Y location approximately one half inch away from thearbor reference knee position 220 in the X direction and toward thecomponent 162. The at least one collimated light source 102, the sensingdevice 104 and/or the reflecting device 106 may then be configured suchthat the lower limit of the pitch diameter at the centerline of field ofview 230 is approximated. A software measurement tool is then placed atthe centerline to find the flank angel crossings at the centerline. Theat least one collimated light source 102, the sensing device 104 and/orthe reflecting device 106 may then be configured to align the minordiameter with the left edge of field of view 230. All subsequentmeasurements rely on moving in pitch lead increments in the X-axisdirection. It should be noted that the pitch lead increments aredetermined by the component selection and are published at the top ofthe Lead Standards readouts. It should be appreciated that, for threadedgages, the truncated measurements will be conducted at thread #2 and thefull form measurements will be conducted at thread #6. The term 4Xrefers to the number of threads for the third lead measurement andindicates that it is being made over a span of four threads and the term/10 indicates that there are ten threads available on this component.

As above, once the flank registration has been performed, the 1^(st)full thread 0° side truncated measurements are conducted, as shown inoperational block 604. This may be accomplished by configuring the atleast one collimated light source 102, the sensing device 104 and/or thereflecting device 106 to the first thread on the 0° side designated asthe truncated thread location. This designation is dependent upon thethread numbers and thus upon the selection of component 162. Using thesilhouette image data, processing device 152 then determines the minorradius, the major radius (for set plug only), the pitch radius, the leadpitch, the lead/trail flank angles and the included angles. The majorradius is determined via the major diameter, which is a compositemeasurement based on the major radius of the 0° and corresponding 180°side of the threads. Thus, the major radius is determined by summing theindividual measurements along the thread flat and dividing by the numberof measurements collected. The number of measurement locations may bedetermined by taking 70% of the thread width, as determined bypredetermined thread tables, and centering them on the center of thethread. This major radius average is then combined from both the 0° andthe 180° sides to get the major diameter. For a gage, this process isperformed for both truncated and full form locations and for a product,this process is performed only for the full form location.

It should be appreciated that all of the measurements taken byconfiguring the positioning stage 128 relative the at least onecollimated light source 102, the sensing device 104 and/or thereflecting device 106 may be conducted by configuring the at least onecollimated light source 102, the sensing device 104 and/or thereflecting device 106 relative to the component, either individually oras a group. As such, the present invention contemplates that any elementof the inspection system 100 may be configured to provide the properperspective to conduct the any of the measurements disclosed and/orcontemplated herein. It should also be appreciated that the inspectionsystem 100 may be configured with digital recognition capability toautomatically determine the component and/or component characteristic tobe measured. For example, the component 162 may include a bar code(either printed and/or etched) that describes the type of componentand/or the component characteristic to be measured.

It should be appreciated that the measurements described hereinabove forlens distortion analysis, predetermined calibration algorithm 500,predetermined component measurement algorithm 600 and/or R&R algorithm700 are preferably accomplished by examining the image data for pixelintensity. This advantageously allows inspection system 100 to locateand record known positions on lens 138, first arbor 132, second arbor134 and/or component 162 as data points. Using these data points, thephysical characteristics of lens 138, first arbor 132, second arbor 134and/or component 162 may be calculated via any method suitable to thedesired end purpose, such as geometric/trigonometric relations,estimations and/or predictions.

In accordance with an exemplary embodiment, it is contemplated thatmultiple measurements may be made at each of the measurement locationsin a manner responsive to predetermined component thread specifications.Moreover, the image data is preferably processed to comprise a pluralityof discrete pixel elements. Processing device 142 then conducts each ofthe measurements by examining each pixel of the plurality of discretepixel elements to determine the physical characteristics of component154 as discussed hereinabove. It is further contemplated that image datamay be displayed via any display device suitable to the desired endpurpose, such as a paper printout, a computer screen, a television, aplasma display and/or a Liquid Crystal Display (LCD). Although thecomponent physical characteristics are determined by processing theimage data as discussed hereinabove, the component physicalcharacteristics may be determined by processing the image data using anydevice and/or method suitable to the desired end purpose. Inspectionsystem 100 may also be operated and/or monitored via a networkconnection, such as a wireless network (cellular, pager, RF), Local AreaNetwork, Wide Area Network, Ethernet and/or Modem.

It is contemplated that processing device 152 may store image data andmeasurement results in a data storage device and/or a volatile memory ofprocessing device 152 (e.g. RAM). It should also be noted that imagedata may be stored in a volatile and/or a non-volatile memory locationwhich may be disposed in any location suitable to the desired endpurpose, such as a remote server. In addition, the data storage devicemay be used to store individual component data and/or group componentdata which may be specific to a desired purpose, such as data for aspecific user, component part and/or a specific end user device, whereinthe component data may include a large range of information, such asuser specific data and/or component part history data.

In accordance with an exemplary embodiment, inspection system 100 mayadvantageously be self-calibrating and automated for inspection ofmultiple components. Moreover, inspection system 100 advantageouslyallows for non-contact measurements which reduce and/or eliminate highinspection costs, operator feel, fatigue, uncertainties and/or error.Inspection system 100 advantageously allows for the generation ofautomatic certificates and information output files. Moreover,inspection system 100 advantageously includes built-in repeatability andreliability (R&R) qualification and testing programs and advantageouslyallows for an extremely fast measurement cycle. The measurement andreporting cycles are typically performed in less than two minutesduration. Furthermore, inspection system 100 advantageously has anaccuracy of about 0.000020 or less. This could never be realized usingthe current “Attributes” or variables measuring system. Also, inspectionsystem 100 is about 25 times faster than using an “Attributes” orvariables measuring system, which will only measure one of the multiplecomponent characteristics required for inspection to satisfy currentspecifications.

A machine-readable computer program code and/or a medium encoded with amachine-readable computer program code for measuring the characteristicsof component 162 using inspection system 100, the code and/or mediumincluding instructions for causing a controller to implement a methodincluding operating inspection system 100, wherein inspection system 100includes collimated light source 102, a sensing device 104 opticallycommunicated with collimated light source 102 and processing device 152,wherein processing device 152 is communicated with the sensing device104, disposing component 162 such that component 162 is associated withinspection system 100, positioning component 162 such that component 162is disposed to partially impede the optical communication between thesensing device 104 and the collimated light source 102, operating thecollimated light source 102 such that a collimated light beam isincident upon component 162 to cause a silhouette of component 162 to bereceived by the sensing device 104, wherein the sensing device 104generates image data responsive to the silhouette, communicating theimage data to processing device 152, processing the image data todetermine desired characteristics of component 162 and displaying thecharacteristics to a user.

In accordance with an exemplary embodiment, the processing of FIGS.12-13, FIG. 19 and FIGS. 22-23 may be implemented by a controllerdisposed internal, external or internally and externally to inspectionsystem 100. In addition, processing of FIGS. 12-13, FIG. 19 and FIGS.22-23 may be implemented through a controller operating in response to acomputer program. In order to perform the prescribed functions anddesired processing, as well as the computations therefore (e.g.execution control algorithm(s), the control processes prescribed herein,and the like), the controller may includes, but not be limited to, aprocessor(s), computer(s), memory, storage, register(s), timing,interrupt(s), communication interface(s), and input/output signalinterface(s), as well as combination comprising at least one of theforegoing.

The invention may be embodied in the form of a computer or controllerimplemented processes. The invention may also be embodied in the form ofcomputer program code containing instructions embodied in tangiblemedia, such as floppy diskettes, CD-ROMs, hard drives, and/or any othercomputer-readable medium, wherein when the computer program code isloaded into and executed by a computer or controller, the computer orcontroller becomes an apparatus for practicing the invention. Theinvention can also be embodied in the form of computer program code, forexample, whether stored in a storage medium, loaded into and/or executedby a computer or controller, or transmitted over some transmissionmedium, such as over electrical wiring or cabling, through fiber optics,or via electromagnetic radiation, wherein when the computer program codeis loaded into and executed by a computer or a controller, the computeror controller becomes an apparatus for practicing the invention. Whenimplemented on a general-purpose microprocessor the computer programcode segments may configure the microprocessor to create specific logiccircuits.

While the invention has been described with reference to an exemplaryembodiment, it will be understood by those skilled in the art thatvarious changes may be made and equivalents may be substituted forelements thereof without departing from the scope of the invention. Inaddition, may modifications may be made to adapt a particular situationor material to the teachings of the invention without departing from theessential scope thereof. Therefore, it is intended that the inventionnot be limited to the particular embodiment disclosed as the best modecontemplated for carrying out this invention.

1. An inspection system, comprising: a collimated light source defininga source optical path, said collimated light source being operable tocause a collimated light beam to propagate along said source opticalpath; a sensing device defining a sensor optical path, said sensoroptical path being substantially perpendicular to said source opticalpath; a positioning device including a positioning device stage; areflecting device, wherein at least one of said collimated light source,said sensing device and said reflecting device is movably disposedrelative to positioning device and wherein said collimated light sourceand said reflecting device is disposed on said positioning device to bewithin said source optical path to receive said collimated light beam,said reflecting device causing a reflected collimated light beam topropagate along said sensor optical path to said sensing device; and aretention mount, said retention mount being disposed within said sensoroptical path such that when a component is retained within saidretention mount, said component blocks at least a portion of saidreflected collimated light beam.
 2. The inspection system of claim 1,wherein said reflecting device is a mirror having an accuracy of betweenabout 1/10 of a wavelength and about ¼ of a wavelength and is disposedin said source optical path at a 45° angle.
 3. The inspection system ofclaim 1, further comprising a system support structure, a basestructure, a bridge structure, a light source mounting structure and asensing device mounting structure, wherein said base structure and saidbridge structure is at least partially constructed from a non-metallicpolymer material.
 4. The inspection system of claim 3, wherein saidpositioning device stage is non-movably associated with a positioningdevice and wherein said positioning device is non-movably disposed onsaid base structure.
 5. The inspection system of claim 4, wherein saidpositioning device includes a motor having a motor controller, whereinat least one of said collimated light source, said sensing device andsaid reflecting device is controllably configurable via said motor. 6.The inspection system of claim 1, further comprising a processingdevice, wherein said processing device is communicated with at least oneof said light source, said sensing device and said positioning device.7. The inspection system of claim 1, wherein said collimated lightsource includes a red Light Emitting Diode (LED) and a collimating lens.8. The inspection system of claim 1, wherein said sensing deviceincludes a high resolution imaging device and a high magnification lenssystem.
 9. The inspection system of claim 8, wherein said highmagnification lens system is a microscope-type tele-centric optical lenssystem having a magnification factor of about 2.6.times.
 10. A methodfor measuring physical characteristics of a component using aninspection system comprising a light source, a sensing device, areflecting device, and a retention mount, at least one of which ismovably associated with the inspection system, the method comprising:associating a component with the inspection system such that saidcomponent is disposed within the retention mount; operating theinspection system to cause the light source to emit a collimated lightbeam propagating along a source optical path; reflecting said collimatedlight beam via the reflecting device to cause a reflected collimatedlight beam to propagate along a sensor optical path such that thereflected collimated light beam is incident upon the component toproduce a component silhouette which is incident upon the sensingdevice; generating image data responsive to said component silhouette;and processing said image data to generate resultant data comprising atleast one of a plurality of physical characteristics of the component.11. The method of claim 10, wherein said operating further includesperforming a lens distortion analysis.
 12. The method of claim 10,wherein said operating further includes calibrating said inspectionsystem via a predetermined calibration algorithm.
 13. The method ofclaim 12, wherein said calibration algorithm includes determining atleast one of X-axis calibration factors, Y-axis first zero diameterfactors, Y-axis second zero diameter factors, a Y-axis second diameterfactor, a Y-axis second 180 diameter factor, a Y-axis tangent correctionfactor and a lens distortion factors
 14. The method of claim 10, whereinsaid plurality of physical characteristics include first thread 0° sidetruncated measurements, second thread 0° side truncated measurements,first thread 180° side truncated measurements and second thread 180°side full form measurements.
 15. The method of claim 14, wherein saidfirst thread 0° side truncated measurements include at least one ofminor radius, major radius, pitch radius, lead pitch, lead flank angle,lead trail angle and at least one included angle and wherein said secondthread 0° side truncated measurements include at least one of minorradius, major radius, pitch radius and lead pitch, said.
 16. The methodof claim 14, wherein said first thread 180° side truncated measurementsinclude at least one of minor radius, major radius, pitch radius andlead pitch and wherein said first thread 180° side full formmeasurements include at least one of major radius, pitch radius and leadpitch.
 17. The method of claim 10, wherein said operating furtherincludes performing a component reliability and repeatability (R&R)measurement, wherein said R&R measurement includes associating a gagewith said inspection system such that said gage is disposed within saidretention mount and calibrating said inspection system a predeterminednumber of times.
 18. The method of claim 10, wherein said operatingfurther includes configuring said inspection system for a predeterminedgage or product to be measured.
 19. The method of claim 10, wheren saidgenerating includes generating said image data via said sensing device.20. The method of claim 10, wherein said processing includes processingsaid image data via a processing device to generate resultant.